The inventor, Cleo McCoy Jr. provides a unique, sleeper unit giving commercial tractor day cab truck operators an option to upgrade their day cab from a sleeping birth to a roomy sleeper unit that retracts and expands. The Retractable Day Cab Sleeper is designed for truck operators who find sleeping births and birth modifications inadequate but don't want to upgrade to a permanent sleeper modification. The Retractable Day Cab Sleeper can also be installed and uninstalled using common tools with no modifications to the existing truck.